drivers/thermal/dove_thermal.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Dove thermal sensor driver
0004  *
0005  * Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch>
0006  */
0007 #include <linux/device.h>
0008 #include <linux/err.h>
0009 #include <linux/io.h>
0010 #include <linux/kernel.h>
0011 #include <linux/of.h>
0012 #include <linux/module.h>
0013 #include <linux/platform_device.h>
0014 #include <linux/thermal.h>
0015
0016 #define DOVE_THERMAL_TEMP_OFFSET    1
0017 #define DOVE_THERMAL_TEMP_MASK      0x1FF
0018
0019 /* Dove Thermal Manager Control and Status Register */
0020 #define PMU_TM_DISABLE_OFFS     0
0021 #define PMU_TM_DISABLE_MASK     (0x1 << PMU_TM_DISABLE_OFFS)
0022
0023 /* Dove Theraml Diode Control 0 Register */
0024 #define PMU_TDC0_SW_RST_MASK        (0x1 << 1)
0025 #define PMU_TDC0_SEL_VCAL_OFFS      5
0026 #define PMU_TDC0_SEL_VCAL_MASK      (0x3 << PMU_TDC0_SEL_VCAL_OFFS)
0027 #define PMU_TDC0_REF_CAL_CNT_OFFS   11
0028 #define PMU_TDC0_REF_CAL_CNT_MASK   (0x1FF << PMU_TDC0_REF_CAL_CNT_OFFS)
0029 #define PMU_TDC0_AVG_NUM_OFFS       25
0030 #define PMU_TDC0_AVG_NUM_MASK       (0x7 << PMU_TDC0_AVG_NUM_OFFS)
0031
0032 /* Dove Thermal Diode Control 1 Register */
0033 #define PMU_TEMP_DIOD_CTRL1_REG     0x04
0034 #define PMU_TDC1_TEMP_VALID_MASK    (0x1 << 10)
0035
0036 /* Dove Thermal Sensor Dev Structure */
0037 struct dove_thermal_priv {
0038     void __iomem *sensor;
0039     void __iomem *control;
0040 };
0041
0042 static int dove_init_sensor(const struct dove_thermal_priv *priv)
0043 {
0044     u32 reg;
0045     u32 i;
0046
0047     /* Configure the Diode Control Register #0 */
0048     reg = readl_relaxed(priv->control);
0049
0050     /* Use average of 2 */
0051     reg &= ~PMU_TDC0_AVG_NUM_MASK;
0052     reg |= (0x1 << PMU_TDC0_AVG_NUM_OFFS);
0053
0054     /* Reference calibration value */
0055     reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
0056     reg |= (0x0F1 << PMU_TDC0_REF_CAL_CNT_OFFS);
0057
0058     /* Set the high level reference for calibration */
0059     reg &= ~PMU_TDC0_SEL_VCAL_MASK;
0060     reg |= (0x2 << PMU_TDC0_SEL_VCAL_OFFS);
0061     writel(reg, priv->control);
0062
0063     /* Reset the sensor */
0064     reg = readl_relaxed(priv->control);
0065     writel((reg | PMU_TDC0_SW_RST_MASK), priv->control);
0066     writel(reg, priv->control);
0067
0068     /* Enable the sensor */
0069     reg = readl_relaxed(priv->sensor);
0070     reg &= ~PMU_TM_DISABLE_MASK;
0071     writel(reg, priv->sensor);
0072
0073     /* Poll the sensor for the first reading */
0074     for (i = 0; i < 1000000; i++) {
0075         reg = readl_relaxed(priv->sensor);
0076         if (reg & DOVE_THERMAL_TEMP_MASK)
0077             break;
0078     }
0079
0080     if (i == 1000000)
0081         return -EIO;
0082
0083     return 0;
0084 }
0085
0086 static int dove_get_temp(struct thermal_zone_device *thermal,
0087               int *temp)
0088 {
0089     unsigned long reg;
0090     struct dove_thermal_priv *priv = thermal->devdata;
0091
0092     /* Valid check */
0093     reg = readl_relaxed(priv->control + PMU_TEMP_DIOD_CTRL1_REG);
0094     if ((reg & PMU_TDC1_TEMP_VALID_MASK) == 0x0) {
0095         dev_err(&thermal->device,
0096             "Temperature sensor reading not valid\n");
0097         return -EIO;
0098     }
0099
0100     /*
0101      * Calculate temperature. According to Marvell internal
0102      * documentation the formula for this is:
0103      * Celsius = (322-reg)/1.3625
0104      */
0105     reg = readl_relaxed(priv->sensor);
0106     reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK;
0107     *temp = ((3220000000UL - (10000000UL * reg)) / 13625);
0108
0109     return 0;
0110 }
0111
0112 static struct thermal_zone_device_ops ops = {
0113     .get_temp = dove_get_temp,
0114 };
0115
0116 static const struct of_device_id dove_thermal_id_table[] = {
0117     { .compatible = "marvell,dove-thermal" },
0118     {}
0119 };
0120
0121 static int dove_thermal_probe(struct platform_device *pdev)
0122 {
0123     struct thermal_zone_device *thermal = NULL;
0124     struct dove_thermal_priv *priv;
0125     struct resource *res;
0126     int ret;
0127
0128     priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
0129     if (!priv)
0130         return -ENOMEM;
0131
0132     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0133     priv->sensor = devm_ioremap_resource(&pdev->dev, res);
0134     if (IS_ERR(priv->sensor))
0135         return PTR_ERR(priv->sensor);
0136
0137     res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
0138     priv->control = devm_ioremap_resource(&pdev->dev, res);
0139     if (IS_ERR(priv->control))
0140         return PTR_ERR(priv->control);
0141
0142     ret = dove_init_sensor(priv);
0143     if (ret) {
0144         dev_err(&pdev->dev, "Failed to initialize sensor\n");
0145         return ret;
0146     }
0147
0148     thermal = thermal_zone_device_register("dove_thermal", 0, 0,
0149                            priv, &ops, NULL, 0, 0);
0150     if (IS_ERR(thermal)) {
0151         dev_err(&pdev->dev,
0152             "Failed to register thermal zone device\n");
0153         return PTR_ERR(thermal);
0154     }
0155
0156     ret = thermal_zone_device_enable(thermal);
0157     if (ret) {
0158         thermal_zone_device_unregister(thermal);
0159         return ret;
0160     }
0161
0162     platform_set_drvdata(pdev, thermal);
0163
0164     return 0;
0165 }
0166
0167 static int dove_thermal_exit(struct platform_device *pdev)
0168 {
0169     struct thermal_zone_device *dove_thermal =
0170         platform_get_drvdata(pdev);
0171
0172     thermal_zone_device_unregister(dove_thermal);
0173
0174     return 0;
0175 }
0176
0177 MODULE_DEVICE_TABLE(of, dove_thermal_id_table);
0178
0179 static struct platform_driver dove_thermal_driver = {
0180     .probe = dove_thermal_probe,
0181     .remove = dove_thermal_exit,
0182     .driver = {
0183         .name = "dove_thermal",
0184         .of_match_table = dove_thermal_id_table,
0185     },
0186 };
0187
0188 module_platform_driver(dove_thermal_driver);
0189
0190 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
0191 MODULE_DESCRIPTION("Dove thermal driver");
0192 MODULE_LICENSE("GPL");